diff options
| author | Eric Dumazet <[email protected]> | 2025-03-12 08:39:07 +0000 |
|---|---|---|
| committer | Paolo Abeni <[email protected]> | 2025-03-18 12:44:59 +0000 |
| commit | 15492700ac41459b54a6683490adcee350ab11e3 (patch) | |
| tree | 647a127cb5c0e71727b4fdfee02830fb4353edc2 /net/ipv4/tcp_input.c | |
| parent | Merge branch 'inet-frags-fully-use-rcu' (diff) | |
| download | kernel-15492700ac41459b54a6683490adcee350ab11e3.tar.gz kernel-15492700ac41459b54a6683490adcee350ab11e3.zip | |
tcp: cache RTAX_QUICKACK metric in a hot cache line
tcp_in_quickack_mode() is called from input path for small packets.
It calls __sk_dst_get() which reads sk->sk_dst_cache which has been
put in sock_read_tx group (for good reasons).
Then dst_metric(dst, RTAX_QUICKACK) also needs extra cache line misses.
Cache RTAX_QUICKACK in icsk->icsk_ack.dst_quick_ack to no longer pull
these cache lines for the cases a delayed ACK is scheduled.
After this patch TCP receive path does not longer access sock_read_tx
group.
Signed-off-by: Eric Dumazet <[email protected]>
Reviewed-by: Jason Xing <[email protected]>
Reviewed-by: Neal Cardwell <[email protected]>
Reviewed-by: Kuniyuki Iwashima <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 5c270cf96678..72382ee4456d 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -334,9 +334,8 @@ static void tcp_enter_quickack_mode(struct sock *sk, unsigned int max_quickacks) static bool tcp_in_quickack_mode(struct sock *sk) { const struct inet_connection_sock *icsk = inet_csk(sk); - const struct dst_entry *dst = __sk_dst_get(sk); - return (dst && dst_metric(dst, RTAX_QUICKACK)) || + return icsk->icsk_ack.dst_quick_ack || (icsk->icsk_ack.quick && !inet_csk_in_pingpong_mode(sk)); } |